Induction-motor.



PATENTED MAY 22, 1906.

B. G. LAMMB.

INDUCTION MOTOR.

APPLICATION rum) mnzmmm.

INVENTOR,

' A TTORNE x.

I V 1' T N E 5355' UNITED STATES BENJABUN G. LAMME, OF PITTSBURG, PENNSY' \YESIINGI'IOUSE ELECTRIC & MANUFACTUH PURATION OF PENNSYLVANIA.

lNDUCTiON-MOTOR.

Specification of Letters Patent.

Patented May 22, 1906.

Application filed February 27,1904. Bax-is! No. l LkL To J1 'u-homif "Indy concern:

Be it known that I, BENJAMIN G. LAMME, a. citizen of the i'nitcd States, and a. resident of Pittsburg. in the county of Allegheny and State of Pennsylvania, have invented a new and useful Ini irovenient in Induction-Motors, of which t. ie following is a specification.

My invention relates to alternating-current motors, and it has for its object to proning, the number of magnetic poles induced high resistance in series with it and is con- 1 by the winding being thereby changed. It has also been proposed to )rovide such a mo- -tor with an auxiliary win ing which is either of high resistance itself or has an external nested in arallel with the main winding in starting t e motor. Such a motor or any other motor using the divided circuit or s litphase arrangement is practically a polyp use machine when starting and Conforms to the laws governing starting conditions of such motors.

It is generally understood that a. poly-phase motor requires a higher secondary resistance when starting than when remain in order to insure a. iarge stsrtin torque. n a singicphase motor it is st more important that the secondary winding have a relatively lowrcsistance when running, since the maximum torque or puli-out" torque of the motor is dependent upon the amount of resistance in the secondary circuit, while in a polyphase' motor the pull-out torque is independent of i such resistance.

Since a single-phase motor such'as I have referred to is a oiyphese motor at the start,

it should have or economical starting a secondai'y winding of relatively high resistance and for rimning a secondary winding of oomparstively lowresistance in order to obtain the desired pull out torque. If: follows, therefore, that if a'secondary winding can'hc so designedthct it will have a high resistance under starting conditions and a low resistance whenthe motor is running, without the employment of ariable resistance or shortcircuiting devices, it will furnish an ideal construction for induction-motors. tion cannotrcsdiiy be obtained if the some number of primary magnetic poles is used in starting as in running; but if the number of poles in starting is different from that when running an arrangement of secondsrywind ing provided by my resent invention can be adopted which wil give circuits having difierentresist euros for starting and running, due to the fact that the secondary circuits are different for different numbers of magnctic poles in the primary member.

My invention is illustrated in the accompanying drawings, in which Fi ure 1 is a diagrammatic view of the windings of" on imiuction-inotor constructed in accordance therewith. Fig. 2 is :1 diagrnninmtic view of the governing switch in the position required for running conditions of tiie'inotor. Fig. 3 is a View in end cl'cvation'of o. secondary member, showing the details of construction; and Fig. 4 is a sectional view on line IV IV of Fig. 3.

In 1 the primary windings A A", B B, and G of the motor 1 are connected by meansof s three-pole double-throw switch 2 for'st-srting conditions of the motor. Singlephsse energy is supplied to the inein primary winding by means of the circuit from the hue conductor L through the switch-blade 3, windings A A and B B; switch-binds 4 to line conductor Hand tothe auxiliary winding bymeans of the circuit from line 'conduc tor L. switch-blade 3, windings O C, resisttime R, switch bhide 5 to the line conductor L. 2X poles are induced by this arrangement-of windings; but if the switch is in the position shown in Fig. 2 the current is re versed in the portion'B B of the main windirrg cndX poles are then induced by the mainpriinary winding, the auxiliary winding (3 'Cgand its connected reaisfience It being thrown out, of circuit.

The secondary member 6 comprises at core 7, harrin slots 8, bcr-conductorsQ, having ends pro'gec'tin beyond the ends of the core and relstiveiy bigh resistance and rings 10 connected, respectively, to the ends of all oi she conducting-bars 9. For starting conditions of the motor or for the larger number of magnetic poles the secondary .circnits have This condicomparatively high resistance, due to the resistance of the endrings.

At points 11, corresponding approximately to the polar pitch when the primary winding is connected for the smaller number of poles or for running conditions of the motor, lowresistance connectors 12 are attached. The secondary circuits for runnin conditions of the motor are then through t e bars to the end rings 10 and through'the nearest low-resistance connectors 12. By this very simple means low-resistance secondary circuits are provided for the motor under running conditions and relatively high resistance secondary circuits for starting conditions.-

-The secondary member may be desi ned for use with either single phase or polyp ase windings on the primary member, and as tively small, as the len man low-resistance connectors 12 may be emp cyed as are desired. The low-resistance connectors may be attached to the highresistance end rings or they may be attached directly to the bar-conductors 9, though it will generally be found most expedient to connect them to /the highresistance end rings, the increased resistance introduced in the secondary circuits by so doing being relath of this high-resistance path is short. T egreater the number of low-resistance connectors or end rings the shoi'lter will be the high-resistance part of the pat y While I have illustrated and described In invention as embodied in a motor having 2 primary magnetic poles when starting and X primary magnetic poles when running, I desire it to be understood that any other suitable ratio may be adopted and that the details of construction may be otherwise-considerably modified Without departing from my invention.

I claim as my invention- 1. In an alternating-current motor, the combination with a primary member having a winding adapted to produce a plurality of numbers of magnetic poles and means for changin from one number of poles to another, oia secondary member com rising a slotted core, conducting-bars in t e coreslots, a high-resistance bod or element that is so connected to said con noting-bars as to be effective when the primary winding roduces thelarger number-of poles, and a owresistance body or element that completes the seconda .circuits when the primary wipding pro uces the smaller number of po es. 1

2. In an alternating-current motor, the combination with a primary member havin a winding adapted to produce a plurality 0 numbers of, magnetic poles and means for ch anging from one number of poles toanother of a secondary member comprising a slotted core, conducting-bars in ,t e core-slots, a high-resistance body or element thatisc9nnectcd to all of said bars and to complete the secondary circuits corres )onding to the lar er number of oles, an a low-resistance bo y or element t at is connected to only a few of said bars to complete the secondary circuits corresponding to the smaller number of poles,

3. In an alternating-current motor, the combination with a primary member havin r a, Winding adapted to produce a plurality 0? numbers of magnetic poles and means for changing from one number of poles to another, of a secondary member comprisin a slotted core, conducting-bars in the cores ots, high resistance end rings connected to all of said bars and low-resistance end rings connected to the high-resistance end rin s at a number of points corresponding to a efinite number of ma netic poles.

4. I n an alternating-current motor, the combination with a primary member having a Winding adapted to produce a lurality of numbers of magnetic poles an means for changing from one number of poles to another, of a secondary member comprising a slotted core, conducting-bars in the core-slots, highresistance end rings connected to all of said bars and adapted, in connection with said bars, to form a high-resistance winding suitable for the larger number of primary magnetic oles, and low-resistance end rin connected to the conductin -bars so as to orm a low-resistance winding or a smaller number of magnetic poles.

11 an alternating-current motor, the combination with a primary member having a winding ada ted to produce NX or X magnetic poles an means for chan 'ng from one number of poles to the other, 0 a secondary member comprising a slotted core, conducting-bars in the core-slots, hi l1-resistance end rings connected to all of sai bars and adapted, in connection therewith, to form-a highresistance winding suitable for NX primary magnetic poles and low-resistance end rings connected withuthe conductin bars so as to form a low-resistance winding or X magnetic poles.

combination with a primary member havin a winding adapted to produce a plurality 0 numbers of magnetic oles and means for changingfromo enum erof poles to another of a secondar iember comprisin a slotted core, conducting-bars in the core-s ots, highresistance 1" connected res ectiv'ely to the ends of all said bars inflow-resistance rin s connected with said bars at intervals suc that they become effective conductors onlywvhen a definite number ,of 1n etic poles are induced by the primary mem er of themotor. i y

7. In an alternating-current.motor, the

combination with a primary member having 5 a winding adapted to produce a pluralit 6. In an alternating-current motor, the i numbers of magnetic oles End means for changing from one num er of poles to another, of a second member comprisin a. slotte core, conducting-bars in the core-s ots, highresistance 11 s connected reapectively to the ends of all c said hers an low-resistance rings connected with said bars at such intervels as to become effective conductors oniv when a. number oi magnetic poies cerresgcn ing to full-s eed running condition of the motor are in ucedby the primary member of the motor.

8'. In an elterna/ti current, motor, the combination with a primary member hevi a winding adapted to produce a plurality 0 numbers of magnetic poles and means for changing from one number of poles to another,

of a secondary member comprising a core, longitudinally-disposed conductors, high re sistence elements connected to the ends cfell of said conductors and low-resistance elements that are connected to the ends of such conductors as will make them e ective por tions' of the secondary circuits when the smaller number of poles is prodnhed by the primary winding In testimony vrhereof I have her unto subscribed my name 1904.

this 12th day of ebruary,

BENJ. G. LAMME.

Witnesses ELISABETH M. STEWART, BIRNEY HINES. 

